Energy conversion systems using nanometer scale assemblies and methods for using same

ABSTRACT

Energy conversion systems utilizing nanometer scale assemblies are provided that convert the kinetic energy (equivalently, the thermal energy) of working substance molecules into another form of energy that can be used to perform useful work at a macroscopic level. These systems may be used to, for example, produce useful quantities of electric or mechanical energy, heat or cool an external substance or propel an object in a controllable direction. In particular, the present invention includes nanometer scale impact masses that reduce the velocity of working substance molecules that collide with this impact mass by converting some of the kinetic energy of a colliding molecule into kinetic energy of the impact mass. Various devices including, piezoelectric, electromagnetic and electromotive force generators, are used to convert the kinetic energy of the impact mass into electromagnetic, electric or thermal energy. Systems in which the output energy of millions of these devices is efficiently summed together are also disclosed.

BACKGROUND OF THE INVENTION

This invention relates to nanometer scale electromechanical systems. Inparticular, the present invention relates to nanometer scaleelectromechanical systems that may be used in various applications, suchas heat engines, heat pumps, or propulsion systems.

Electromechanical systems that rely on molecular motion are known. Forexample, U.S. Pat. No. 4,152,537 (the “'537 patent”), describes anelectricity generator that produces electrical energy from the randommovement of molecules in a gas, and the uneven distribution of thermalenergy in different molecules of the gas, which is at an overall uniformtemperature.

Other such systems are described in, for example, U.S. Pat. Nos.3,365,653; 3,495,101, 2,979,551; 3,609,593; 3,252,013 and 3,508,089.These systems produce electricity or devices driven by electricity, suchas an oscillator, based on molecular motion and thermal energy.

One problem common to all of these systems is the low level of outputpower when compared to the amount of power required to operate thesystems. For example, such systems often require a certain amount ofenergy to maintain the systems at a constant overall temperature. Whilethe '537 patent attempted to address some of the known deficiencies insuch systems, the electricity generator described therein also suffersfrom similar deficiencies. For example, the '537 patent attempts to heatthe thermocouple junction between two dissimilar materials by simplybeing in contact with a gas-molecule having an above-average speed. Inaddition, the '537 patent utilizes an array of electrical rectifiers(see, e.g., rectifier bridge 40 in FIGS. 2 and 4) that may havedifficulty in operating properly due to the infinitesimally smallvoltages produced at the molecular scale.

Moreover, as the use of electronic devices continues to flourish, thereis an ever increasing need to provide more efficient and/or quieter waysto cool the components that are typically the heart of such devices. Forexample, most personal computers include one or more fans that arerequired to maintain the temperature of the microprocessor within acertain operational range. These fans are often noisy, and often resultin large quantities of dirty air being pulled through the computer fromthe air intakes.

Accordingly, it is an object of the present invention to providenanometer scale electromechanical systems that efficiently convertmolecular-level energy into another form that can be used at amacroscopic scale.

Another object of the present invention is to provide nanometer scaleelectromechanical systems that efficiently convert molecular-level heatenergy into useful mechanical and/or electrical energy.

A still further object of the present invention is to provide nanometerscale electromechanical systems that utilize molecular-level energy tocreate a pressure differential on a surface of an object to propel theobject in a controllable direction.

An even further object of the present invention is to provide nanometerscale electromechanical systems that utilize molecular-level energy toheat or cool an external substance.

SUMMARY OF THE INVENTION

The nanometer scale electromechanical systems of the present inventionefficiently convert molecular-level energy from one form into anotherform by reducing the velocity of the molecules within the workingsubstance. These systems may include, for example, a heat engine thatconverts molecular-level heat energy into useful mechanical orelectrical energy. Such systems may also include a heat pump thatutilizes molecular-level energy to either heat or cool a substance. Forexample, a system of the present invention may be mounted to amicroprocessor as the primary cooling device, so that little or no fanswould be necessary. In addition, these systems may also includepropulsion systems in which molecular-level energy is utilized to createa pressure differential on the surface of an object, thereby providingthe ability to propel that object in a controllable direction.

Nanometer scale electromechanical systems constructed in accordance withthe present invention may include a large number of nanometer-sizedobjects, such as paddles, impact masses, and/or tubes, that are placedin a liquid or gas. These objects may be sized on the order of severalnanometers per side, and may have a thickness on the order of about oneor two nanometers. One side of the paddle is connected to a flexible,spring-like, attachment, that couples the paddles to a common base. Alsoattached to each paddle is some form of generator device, such as apiezoelectric, electromotive force or electrostatic generator, thatconverts random molecular motion into electrical, electromagnetic orthermal energy.

The nanometer-sized paddles, in conjunction with an associatedgenerator, reduce the speed of individual molecules which results in areduction of thermal energy within the working fluid. The generatedelectrical energy may be converted back to thermal energy at a highertemperature than the working fluid and used to establish a temperaturedifferential that is capable of performing useful work. Essentially, thepaddles are configured to be immersed in a working substance. Thepaddles move in a random manner within the working substance due tovariations in the thermal motion of the molecules of the workingsubstance. This movement necessarily results from collisions between themolecules of the working substance and the paddles which are largeenough to cause the paddles to oscillate. The kinetic energy from thisoscillation may then be converted into electrical, electromagnetic orthermal energy by various methods, as described above.

Nanometer scale electromechanical systems constructed in accordance withthe present invention also provide components that efficiently collectand sum the outputs of the numerous paddles so that a useful electricaloutput is produced. For example, one embodiment of the present inventionincludes the use of an array of resistive elements, one for each paddle,that are in contact with one side of the thermocouple. The other side ofthe thermocouple is placed in thermal contact with something else thatis at an ambient temperature (such as a gas or liquid). Each of thethermocouples produces an output (i.e., a DC current and voltage) thatcan be summed through a simple series connection to produce an output,depending on the number of paddles and configuration, on the order ofseveral milliwatts.

In one particular embodiment, a nanometer scale electromechanical systemconstructed in accordance with the present invention may include anarray of nanotubes, such as tubes made of carbon, which are coupledbetween two plates of a capacitor. One of the tubes is physicallyconnected to one plate of the capacitor, while the other end is free tomove. The entire assembly is immersed in a fluid (i.e., a liquid or agas). A voltage is applied to the capacitor (across the plates), whichcreates an electric field (“E”) that keeps the length of the tubesperpendicular to the surface of the capacitor plate. The “free” ends ofthe tubes, which are immersed in a working substance, move erraticallydue to collisions between the molecules of the working substance and thetubes, causing some of the tubes collide into each other. Kinetic energyof the colliding tubes, as well as other energy, may be converted forone or more useful purposes, as previously described.

In another embodiment of the present invention, numerous nanotubes areconnected at each end to an electrically and thermally conductive rail.Each of the tubes is installed such that there is slack, or bend, in thetube. The slack permits the tubes to vibrate in response to randompressure variations from surrounding fluid (gas or liquid). In thiscase, an external magnetic field (“{overscore (B)}”) is applied to theentire assembly which is perpendicular to the tubes and rails. Heatgenerated in the tubes, from the induced current, flows down the tubesto the thermally conductive rails, which are attached to a thermallyconductive plate.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and advantages of the present invention willbe apparent upon consideration of the following detailed description,taken in conjunction with accompanying drawings, in which like referencecharacters refer to like parts throughout, and in which:

FIG. 1A is an illustrative schematic diagram of a portion of a nanometerscale electromechanical system constructed in accordance with thepresent invention;

FIG. 1B is an illustrative schematic diagram of one embodiment ofconversion circuitry constructed in accordance with the principles ofthe present invention;

FIG. 2 is an illustrative schematic diagram of a portion of anothernanometer scale electromechanical system constructed in accordance withthe principles of the present invention;

FIG. 3 is a perspective view of a portion of a nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 4 is a perspective view of a portion of another nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 5 is an illustrative schematic diagram of a nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 6 is an illustrative schematic diagram of another nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 7 is a perspective view of another nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 8 is an illustrative schematic diagram of a portion of thenanometer scale electromechanical system of FIG. 7;

FIG. 9 is another illustrative schematic diagram of a portion of thenanometer scale electromechanical system of FIG. 7;

FIG. 10 is a cross-sectional view of another nanometer scaleelectromechanical system constructed in accordance with the principlesof the present invention;

FIG. 11 is a perspective, partial cross-sectional view of anothernanometer scale electromechanical system constructed in accordance withthe principles of the present invention;

FIG. 12 is an illustrative schematic diagram of a portion of thenanometer scale electromechanical system of FIG. 11;

FIG. 13 is a perspective, partial cross-sectional view of anothernanometer scale electromechanical system constructed in accordance withthe principles of the present invention;

FIG. 14 is an illustrative schematic diagram of a portion of thenanometer scale electromechanical system of FIG. 13;

FIG. 15 is a cross-sectional plan view of the nanometer scaleelectromechanical system of FIG. 13 taken along line 14—14;

FIG. 16 is an illustrative schematic diagram of a portion of thenanometer scale electromechanical system of FIG. 13; and

FIG. 17 is an illustrative schematic diagram of an electromechanicalpropulsion system constructed in accordance with the principles of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1A shows an illustrative example of a portion of a nanometer scaleelectromechanical system constructed in accordance with the presentinvention. The portion shown includes an impact mass in the form ofpaddle 100, a restraining member 102, an generator device 104 (whichprovides an electrical output at leads 106), and a base 108 (which istypically thousands or millions times larger than paddle 100). Paddle100 is attached to base 108, which may be thermally conductive, but neednot be, so that paddle 100 may be moved within a predetermined range ofdistance in one or more directions (such as laterally, or up and down).A complete energy conversion system using nanometer scale assemblieswould typically include a million or more of the devices shown in FIG.1A, as will become more apparent below (see, for example, FIGS. 5 and6).

Paddle 100 may be constructed, for example, from a substance such ascarbon or silicon, although persons skilled in the art will appreciatethat variations may be made in the fabrication materials of paddle 100without departing from the spirit of the present invention. Moreover,paddle 100 can generally be manufactured using known semiconductorfabrication techniques such as sputtering, etching, photolithography,etc.

In addition, each paddle 100 may be constructed to be about fivenanometers on each side, and have a height of about one to twonanometers—this size being selected so that the effects of Brownianmotion are large enough to overcome inertia of paddle 100 and the springconstant of restraining member 102. Persons skilled in the art willappreciate that the specific size of paddle 100 is not critical to thebasic operation of the present invention, provided that paddle 100 isable to move in an irregular manner within the working substance as aresult of random variations in the velocity of the working substancemolecules that strike paddle 100.

Also shown in FIG. 1A, is molecule 110 which is shown as having bouncedoff of paddle 100, and is now traveling at a reduced velocity. Personsskilled in the art will appreciate that, while some molecules will havea reduced velocity as a result of the impact, others may exhibit littlechange in velocity, and others may actually achieve an increasedvelocity. In general however, and in accordance with the presentinvention, the impact of molecule 110 with paddle 100 results, on theaverage, with a reduction in velocity.

The molecule is a molecule of the working substance of the system, whichis preferably a fluid (i.e., a gas or a liquid), but may also be asolid. The fluid may be kept at atmospheric pressure or it may be keptat an elevated pressure, such as, for example a pressure in excess ofabout 15 PSI. As described above, the pressure of the working fluid mayhave an impact in the output provided by the system. Molecule 110strikes paddle 100, thereby causing molecule 110 to experience areduction in velocity. The reduction in velocity corresponds to areduction in temperature of the working substance of the system.

The reduction in velocity of molecule 110 is caused by paddle 100 inconjunction with device 104, which may be any one of a variety ofdevices without departing from the present invention. For example,device 104 may be a piezoelectric device, or it may be a electromotiveforce or electrostatic generator. In each instance, device 104 convertsthe energy of the impact mass, from the impact of molecule 110 intoimpact mass 100, into electrical energy that is output via leads 106.

The amount of electrical energy output via leads 106, even under themost favorable conditions will be very small. For example, the output ofpaddle 100 may be on the order of about 10⁻¹² watts, depending on thesize of the device and various other factors. Accordingly, for thesystem to provide useful output power, such as, for example, a fewmicrowatts, the system requires that millions of such paddles befabricated, and that they be connected together in some fashion, so thatthe outputs of all, or substantially all, of them can be summed into asingle output signal.

If a million or so of paddles 100 were arranged together in an array(see, for example, FIGS. 5 and 6), one way to sum all of the energy fromeach of those paddles would be to couple the leads 106 of each paddle100 to resistive element 112 (see FIG. 1B), and have resistive element112 be in thermal contact with one side 114 of thermocouple 116. Theother side 118 of thermocouple 116 would then be in thermal contact witha heat sink or some other substance at ambient temperature (which mayeven include the working substance itself). Thermocouple 116 is athermoelectric generator that, in response to a temperaturedifferential, produces a voltage across a pair of leads and, if theleads are connected to a load, a DC current.

Variations in molecular impacts on paddle 100 will cause an increase inthe temperature of resistive element 112, which will then be convertedinto electrical energy by thermocouple 116 and output via leads 120. Oneadvantage of the use of resistive elements is the fact that, because aresistive load is independent of current/polarity direction, there is noneed for a rectifier associated with each paddle. Thus, in accordancewith the present invention, even infinitesimal voltages produced by theimpacts of molecules 110 on paddles 100 can be used to heat resistiveelements to useful values. Each thermocouple in the array, in turn,produces an output having a DC voltage, and current if connected throughan electrical load. All of these outputs can then be connected togetherin series to produce an output of at least several microwatts.

If additional power is needed, numerous subassemblies of paddles couldbe coupled together in series. For example, if a given subassembly wasformed to include an array of paddle assemblies in which each assemblyoccupied approximately one hundred square nanometers, a squarecentimeter assembly would include roughly one trillion paddleassemblies. Then, any number of the one square centimeter subassembliescould be coupled together in series or parallel to achieve the desiredratio of voltage and current.

In addition, with a combined output on the order of approximately 700mV, the output of each one square centimeter assembly could even bemanipulated using conventional semiconductor switches. Thus, a givencomponent could be fabricated by fabricating many one square centimeterassemblies next to each other on a thin, flexible sheet of material(such as aluminum) in a continuous process. The resultant sheets ofmaterial could then be cut up and rolled into a tube, similar to thefabrication process of some capacitors.

Persons skilled in the art will appreciate that the electrical output ofthese devices per unit surface area is proportional to the pressure ofthe fluid, the average temperature of the fluid, the oscillationfrequency of the paddle and the mass of the fluid molecules used(regardless of whether the fluid is a gas or a liquid). The output perunit area is inversely proportional to the size of the paddle and thedensity of the paddle material. Accordingly, by choosing a heavymolecule gas, such as xenon, or by using a fluid heavily laden withparticulates, such as air laden with carbon molecules, and/or byimmersing the paddles in the gas at elevated pressure, such as 100 timesatmospheric pressure, the power output of the units can be increased bya factor of over 100, as compared with units operating in air atatmospheric pressure.

FIG. 2 shows a alternate embodiment of the paddle assembly shown in FIG.1. In particular, the assembly in FIG. 2 varies from that in FIG. 1 inthat restraining member 102 is coupled to a housing 208 instead of base108. Housing 208 is a thermally conductive chamber which includes theability to receive thermal inputs (shown as “Q” in FIG. 2). In thisembodiment, the influx of heat Q is converted into electrical energythat is output via each of leads 106. In addition, while the assemblyshown in FIG. 1 does not include a housing, it may be desirable, but iscertainly not required, to locate that assembly in a housing as well, ifonly to protect it from contaminates.

The embodiment shown in FIG. 2 may be used to illustrate one of theadvantages of the present invention, in that the nanometer scale energyconversion systems of the present invention may be used as a heat pump.For example, thermally conductive housing 208 will be cooled as a resultof the molecular impacts on paddles 100 and subsequent conversion of thepaddle kinetic energy into electrical energy. Warm or hot air may becooled by blowing it across housing 208. On the other hand, resistiveload 112 may be connected in series with leads 106, which results in thetemperature of resistive load 112 being raised. Cool air may be warmedby blowing it over resistive load 112. In this manner, the same assemblymay be used to heat an external substance or to cool an externalsubstance.

FIG. 3 shows another embodiment of a portion of a nanometer scaleelectromechanical system 300 constructed in accordance with theprinciples of the present invention. The portion of system 300 shown inFIG. 3 includes three paddle assemblies 302, 322 and 342, which are eachcoupled to one of piezoelectric generators 304, 324 and 344. Each ofpaddle assemblies 302, 322 and 342 is somewhat similar to paddleassembly 100 of FIG. 1, in that each paddle assembly shown in FIG. 3also includes a substantially planar surface that is held in place suchthat it may move in response to molecular impacts. In this instance,paddle assemblies 302, 322 and 342 are attached at one end which isgenerally referred to by numeral 380 in FIG. 3.

The piezoelectric generators are each formed from a portion ofpiezoelectric material and a resistor assembly. Generator 324, forexample, which is substantially similar to generators 304 and 344, isillustrated to show the division between piezoelectric material 326 andresistor assembly 328. However, the division between the piezoelectricportion and the resistor assembly may also be observed in FIG. 3 forgenerators 304 and 344.

Resistor assemblies 308, 328 and 348 are each connected to two wiresthat are made from different material. For example, each of wires 307,327 and 347 are made from one material, while wires 309, 329 and 349 areall made from a different material. The other end of all of the wiresare connected to a series of heat sinks 360, which are themselvesmechanically coupled to a substrate 370 (which may, for example, be asilicon substrate). It should be noted that paddle assemblies 302, 322and 342 are only connected to substrate 370 at one end, generallyreferred to by reference number 380, so that, for example, the paddleassemblies may easily vibrate up and down.

System 300 operates in accordance with the present invention as follows.The entire system is immersed in a fluid (i.e., a liquid or a gas) thatis the working substance. Statistical variations in the velocity ofworking substance molecules that strike paddle 302, for example, causethe free end of paddle 302 to vibrate up and down. The up and downmotion of paddle 302 causes strain in piezoelectric material 306, whichgenerates a voltage between lower conductive outer layer 385 and upperconductive layer 387 of material 306.

Outer conductive layers 385 and 387 of material 306 are in contact withresistor assembly 308, so that a current flows from material 306 throughresistor 308 and back to material 306. The current through resistor 308heats up the resistor, which is coupled to one side of thethermoelectric generator formed by wires 307 and 309 (which, asdescribed above, are made from different materials). The other side ofthe thermoelectric generator (which may also be referred to as athermocouple) is coupled to heat sinks 360, which are at a lowertemperature. Persons skilled in the art will appreciate that otherdevices may be used, such as thermal to electric heat engines (such as,for example, a thermionic heat engine), rather than thermoelectricgenerators described herein, without departing from the spirit of thepresent invention.

The temperature differential causes the thermoelectric generator toproduce a voltage, which, as described more fully below, may be combinedwith the voltages from other paddle assemblies to provide a systemoutput voltage. These voltages, in accordance with the presentinvention, may be coupled together in series to produce an electricaloutput at a useable level from system 300. The process of summingvoltages from each paddle assembly is more particularly illustrated withrespect to FIGS. 5 and 6 below.

Persons skilled in the art will appreciate that, while system 300 hasbeen described as a system that converts kinetic energy of the impactmass (resulting from the Brownian motion of the impact mass immersed ina working substance) to AC electrical energy to thermal energy and to DCelectrical energy, system 300 may, with minor changes, directly produceDC electric energy as a result of this kinetic energy.

In particular, it should be noted that movement of paddle 302 upward andthen downward to its resting location generates a voltage of onepolarity. Movement downward and then upward back to the resting locationgenerates a voltage in the opposite polarity. Thus, in accordance withthe present invention, paddles 302 can be substantially limited tomoving between a neutral point (i.e., the resting location) and a singlelimit point (versus normal vibration that goes from a first limit point,through the neutral point to a second limit point and back).

Accordingly, if paddle 302 were limited to “upward” movement by placingan object at location 303 (i.e., toward the free end of paddle 302), theoutput voltage would be limited to one polarity (essentially, pulsatingDC). In such a configuration, the outputs of the piezoelectricgenerators (such as generator 304) could be directly coupled together inseries, which would eliminate the need of, for example, resistorassembly 308, wires 307 and 309 and heat sinks 360, while stillproviding useful levels of electrical power without the need forrectification circuitry.

FIG. 4 shows another embodiment of a portion of a nanometer scaleelectromechanical system 400 constructed in accordance with theprinciples of the present invention. The portion of system 400 shown inFIG. 4 includes three paddle assemblies 402, 422 and 442, which are eachcoupled to one of piezoelectric generators 304, 324 and 344 (which weredescribed above with respect to FIG. 3).

As shown in FIG. 4, each of the paddle assemblies 402, 422 and 442includes an impact mass 490 and a multitude of nanotubes 492 that aremounted on impact mass 490 such that they are substantiallyperpendicular to impact mass 490. Each of nanotubes 492 may, forexample, be constructed of a material such as carbon, having a diameterof about approximately 2 nanometers and a height of about approximately25-50 nanometers (persons skilled in the art will appreciate that thedimensions of nanotubes 492 may be varied without departing from thespirit of the present invention). Moreover, the stiffness and alignmentof nanotubes 492 may be controlled by the application of a staticvoltage, such as that shown in FIG. 7, and described below.

System 400 operates in very much the same way as previously describedfor system 300. Statistical variation in gas pressure about paddles 402,422 and 442 cause the free end of paddle 402 to vibrate up and down,thereby causing strain in the piezoelectric material, which generates avoltage on the conductive outer layers of the piezoelectric material. Insystem 400, however, the up and down motion of the paddles in system 400may be enhanced by nanotubes 492, which cause additional molecularimpacts.

The outer conductive layers of the piezoelectric material are in contactwith resistor assembly, so that a current flows, which heats up theresistor. The thermoelectric generator formed, for example, by wires 307and 309 is between the heated resistor and the heat sinks 360, which areat a lower temperature. The temperature differential causes thethermoelectric generator to produce a voltage.

FIGS. 5 and 6 show two similar configurations of nanometer scaleelectromechanical systems 500 and 600, respectively, that are eachconstructed in accordance with the principles of the present invention.Systems 500 and 600 each include a multitude of paddle assemblies 302,coupled to generators 304 which are themselves, coupled to wires 307 and309 that are connected to heat sinks 360. This may be more apparent byviewing the dashed box showing where the portion of system 300 of FIG.3, for example, may be found. As shown in FIGS. 5 and 6, systems 500 and600 each include ninety paddle assemblies 302 and the associatedcomponents (i.e., generators, wires and heat sinks).

In practice, nanometer scale electromechanical systems constructedaccordance with the present invention may include a billion or morepaddle assemblies on a single substrate. The output voltage across eachpair of wires extending from each thermoelectric generator on a singlesubstrate are, in accordance with the present invention, coupledtogether in series to provide a single output signal for the system.That output signal may have a voltage that may be on the order of avolt, depending on the number of individual components used and thespecific fabrication techniques used to manufacture those components.The primary difference between systems 500 and 600, is that system 500includes a load resistor 502 while system 600 does not.

Persons skilled in the art will appreciate that, while load resistor 502is shown as being mounted to substrate 370, it may be preferable tothermally isolate load resistor from the working fluid substrate 370 isimmersed in so that heat dissipated by load resistor 502 does not affectthe temperature of the working fluid.

FIG. 7 shows another embodiment of a nanometer scale electromechanicalsystem 700 constructed in accordance with the principles of the presentinvention. System 700 includes an array of nanotubes 702 located betweenan upper plate 704 and lower plate 706 of capacitor 708, and a source ofvoltage 710, which is also coupled across the plates of capacitor 708.Each of nanotubes 702 may, for example, be constructed of a materialsuch as carbon, having a diameter of about approximately 2 nanometersand a height of about approximately 25-50 nanometers (persons skilled inthe art will appreciate that the dimensions of nanotubes 702 may bevaried without departing from the spirit of the present invention).

One end of each nanotube 702 is fixed to lower plate 706 of capacitor708. The other end of each nanotube 702 is free to move. The entireassembly 700 is then typically immersed in a fluid (i.e., gas orliquid). Once a voltage V is applied from source 710 across the platesof capacitor 708, an electric field E is produced that creates a forcethat helps keep the length of nanotubes 702 oriented substantiallyperpendicular with the surface of capacitor plates 704 and 706.Statistical variations in the speed and direction of working fluidmolecules which strike nanotubes 702 cause statistical variations influid pressure about nanotubes 702 which, in turn, cause nanotubes 702to move erratically as illustrated in FIGS. 8 and 9.

As shown in FIG. 8, nanotubes 802 and 822 (which are simply any twoadjacent nanotubes 702) are substantially perpendicular to lowercapacitor plate 706 even though individual molecules 110 have recentlyimpacted each nanotube. In this instance, there is no variation in thegas pressure on either side of the nanotubes, and the tubes remainerect. Persons skilled in the art will appreciate that, while theinteraction of two nanotubes is shown, the molecular impact of thousandsor millions of nanotubes would be occurring simultaneously.

FIG. 9, on the other hand, illustrates the effect of statisticalvariation in fluid pressure about nanotubes 902 and 922 (which, likenanotubes 802 and 822, are simply two adjacent nanotubes 702) resultingfrom variations in the thermal movement of working fluid molecules,which cause the free ends of nanotubes 902 and 922 to collide atlocation 930. The kinetic energy of colliding nanotubes 902 and 922 ispartially converted into thermal energy as a result of the friction fromcontact and as the tubes slide past each other. The thermal energy isconducted down the length of nanotubes 902 and 922 to thermallyconductive plate 706.

In addition, as illustrated in FIGS. 8 and 9, each of nanotubes 702 (ornanotubes 802, 822, 902 and 922) has an electrostatic charge due to theelectric field E between capacitor plates 704 and 706. The collision ofnanotubes 902 and 922 further dissipates tube kinetic energy byaccelerating electrical charges, which in turn produces electromagneticwaves, at the free end of the nanotubes. In this manner, a portion ofthe kinetic energy of the working fluid is transferred to lowercapacitor plate 706, and to the surrounding space, as electromagneticenergy resulting in a net effect of cooling the working substance andheating lower capacitor plate 706. This temperature differential maythen be used to directly heat or cool an area of space or to power aheat engine.

FIG. 10 shows another embodiment of a nanometer scale electromechanicalassembly 1000 constructed in accordance with the present invention.Assembly 1000 includes many nanotubes 1002, all connected to a base1004. Unlike the previous embodiments, nanotubes 1002 are closed attheir upper end such that gas molecules are captured within eachnanotube 1002. In addition, as shown in FIG. 10, at least one moleculein each nanotube 1002 is electrically charged (for example, individualnanotube 1012 includes at least one positively charged molecule, whileindividual nanotube 1022 includes at least one negatively chargedmolecule).

Assembly 1000 is configured such that the net charge of nanotubes 1002in the assembly is zero, with half of the tubes including positivecharges and the other half including negative charges. In thisembodiment, as the charged molecules bounce against the nanotube wallsand the other molecules within the nanotubes, an acceleration of chargeresults that generates electromagnetic waves which pass through the tubeassembly to the surrounding space. As a result of the electromagneticradiation, gas within nanotubes 1002 cools, which cools thermallyconductive base 1004. In this instance, the reduced temperature of base1004 may be utilized to cool a volume of fluid, or can be used as the“cold side” of a heat engine, as will be apparent to persons skilled inthe art.

FIG. 11 shows a nanometer scale electromechanical assembly 1100constructed in accordance with the principles of the present invention.Assembly 1100 includes a series of nanometer members 1102 that areconnected between a pair of electrically and thermally conductive rails1104 and 1106. In this embodiment, nanometer members 1102 are carbonnanotubes and each one of nanotubes 1102 is provided with some slack,which enables the nanotubes to vibrate in reaction to random pressurevariations in the surrounding working substance. Rails 1104 and 1106 aremounted to and in thermal contact with thermally conductive base 1108.

It should be noted that various other nanometer members may be used inaccordance with the present invention instead of the nanotubes describedherein. For example, the principles of the present invention may becarried out using essentially any electrically conductive material thatmay be formed into very small fibers. This may include simple carbonfibers instead of nanotubes.

The nanometer members shown in FIGS. 11 and 12 (as well as those ofFIGS. 13-16 discussed below) perform additional functions when comparedto, for example, the previously described paddles. For example, thenanometer members of FIGS. 11-16 all function as the impact mass whilecontributing to the functions of the previously described restrainingmember and generator device. In addition, the nanometer members of FIGS.11 and 12 also function as the resistive element (FIGS. 13-16 includeresistive element 1304, as described more fully below).

Attached to thermally conductive base 1108, in accordance with theprinciples of the present invention, is a thermal insulation material1110 that covers at least a majority of the otherwise exposed portionsof conductive base 1108. The use of insulation 1110 aides in theprevention of thermal energy losses. Moreover, persons skilled in theart will appreciate that similar insulation may be utilized in thepreviously described embodiments to further increase the efficiency ofthose systems and assemblies.

An external magnetic field (shown as “{overscore (B)}” in FIG. 11)penetrates assembly 1100 which is perpendicular to rails 1104 and 1106and base 1108. The operation of assembly 1100 is illustrated in FIG. 12,which shows a portion of rails 1104 and 1106, and includes twoindividual nanotubes 1202 and 1222 (which are simply two adjacentnanotubes 1102). Nanotubes 1202 and 1222, which are immersed in aworking substance, move in an irregular manner from the relaxed “rest”position (shown as straight dotted lines 1203 and 1223) due to randomvariations in the thermal motion of the molecules of the workingsubstance. Motion of nanotubes 1202 and 1222 in the presence of themagnetic field {circumflex over (X)}{overscore (B)} induces an electricfield E along the length of nanotubes 1202 and 1222 (as shown in FIG.12).

Field E induces current “i” to flow that flows from one nanotube, downone rail, across the other nanotube, and up the other rail (which, whileillustrated as a clockwise current, may be counterclockwise at someother point in time when the direction of the motion of the nanotubeschanges, thereby producing AC current). The current flow through thenanotubes and rails causes resistive heating and causes heat to travelalong the nanotubes and rails to conductive base 1108. Fluid (either gasor liquid) surrounding the nanotubes cools while base 1108 heats up,thereby establishing a temperature differential that may be used in avariety of ways (such as the heat pump, or heat engine previouslydescribed).

FIGS. 13-16 show a further illustration of the use of insulation inaccordance with the principles of the present invention in assembly1300. Assembly 1300 is similar to assembly 1100 of FIG. 11 in manyaspects. Assembly 1300 also includes nanotubes 1302 that are immersed ina working substance. Moreover, as described above with respect tonanotubes 1102, nanotubes 1302 are installed with slack such that theycan move in an irregular manner due to random fluctuations in thethermal motion of the molecules of the working substance.

Assembly 1300 also relies on an external magnetic field {overscore (B)}.As previously described, motion of nanotubes 1302 through the magneticfield {overscore (B)} induces an AC current to flow, which in this case,is directed through a resistor 1304 located directly below each ofnanotubes 1302. The value of resistor 1304 may be chosen to be abouttwice the resistance of the nanotube, in which case the majority ofpower generated is dissipated as heat through the resistor.

Assembly 1300 is configured such that the resistors 1304 are locatedbelow insulating layer 1310 and above thermally conductive sheet 1312.This results in directing most of the generated power and heat downwardinto assembly 1300, rather than up into the working fluid. Moreover,rather than using rails, assembly 1300 utilizes posts 1306, so that onlya limited amount of surface area that is at an elevated temperature isexposed to the working fluid. Resistors 1304, posts 1306 and theresistor leads are electrically insulated from thermally conductivesheet 1312 by a thin layer of electrical insulation 1314 that isdeposited on top of conductive layer 1312.

Heat from resistor 1304 raises the temperature of thermally conductivesheet 1312. The bottom of conductive sheet 1312 is in thermal contactwith a “HOT” portion 1330 of a thermoelectric generator 1334 (sheet 1312is electrically insulated from hot portion 1330 via electricallyinsulating sheet 1316). A second thermally conductive sheet 1322 is inthermal contact with a “COLD” portion 1332 of a thermoelectric generator1334 (while the two are electrically insulated by thin layer 1318). Inthis manner, generated heat is directed from resistors 1304 downwardthrough assembly 1300 and out the bottom of lower layer 1322.

Temperature differentials between the HOT and COLD portions (1330 and1332, respectively) of thermoelectric generator 1334 create a DC voltageacross each junction. By interconnecting a multitude of these junctionstogether in series, assembly 1300 may be used to provide a useablevoltage which may be about at least 1 volt, as was previously describedfor the other embodiments. When assembly 1300 is used to drive a load,such that the load is connected in series to thermoelectric generator1334, and the working fluid is being cooled or maintained within apredetermined temperature range, improved efficiency of the system willbe obtained by keeping the load away from the working fluid so thatdissipated power in the load does not affect the temperature of theworking fluid.

Moreover, as can be viewed most clearly in FIG. 15, additional layers ofthermal insulation are used to separate the HOT portions of assembly1300 from the COLD portions of assembly 1300. In particular, assembly1300 also includes insulating layer 1342 sandwiched between conductivesheet 1312 (actually, as shown, layer 1342 is below electricalinsulating layer 1316) and COLD portion 1332. Insulating layer 1352, onthe other hand, is located between a second conductive sheet 1322 andHOT portion 1330 (actually, as shown, layer 1352 is underneathelectrically insulating layer 1318). These insulating layers increasethe temperature difference between HOT and COLD portions ofthermoelectric generator, thus increasing the electrical output ofthermoelectric generator 1334.

Operation of assembly 1300 is similar to assembly 1100, and isillustrated with respect to FIG. 16. Movement of nanotubes 1302 in theexternal magnetic field {circumflex over (X)}{overscore (B)} induces acurrent “i” to flow as shown in FIG. 16. In this case, though, thecurrent from each individual nanotube 1302 remains in a self-containedcircuit, along with the corresponding resistor 1304. For example, thecurrent induced in individual nanotube 1342 remains in an “isolated”circuit with individual resistor 1344, rather than interacting with anadjacent nanotube, as was described with respect to assembly 1100. Onceagain, persons skilled in the art will appreciate that, while themovement of two nanotubes is shown, the movement of millions or billionsof nanotubes would be occurring simultaneously.

Persons skilled in the art should appreciate that, while it may appearthat an individual thermoelectric generator portion is available foreach individual nanotube 1302, is will likely be impractical and orprohibitively expensive to implement such a configuration. Thus, it maybe more likely that, in accordance with the present invention, several,if not millions, of nanotubes 1302 will be thermally coupled to eachindividual portion of thermoelectric generator 1334.

FIG. 17 shows a propulsion system 1700 constructed in accordance withthe present invention in which an object immersed in a working substanceis moved in a controllable direction as a result of variations inmolecular impacts of working substance molecules into the object. System1700 includes sphere 1702 and a series of electromagnets 1704, 1706,1708, 1710, 1712 and 1714 (1712 and 1714 are shown as a single pair ofdotted lines) arranged axially about electronics core 1716 (axiallysimply refers to the fact that there is one electromagnet locatedparallel to each of the six sides of electronics core 1716, and thateach electromagnet may have its center aligned with an imaginary axisextending perpendicular to the core surface). These electromagnets,along with a control system form a drive system that, as set forth inmore detail below, helps to propel sphere 1702.

Sphere 1702 may be any three-dimensional object. Although a sphere isshown, other shapes such as a cube, cylinder, etc., may be used. Thesurface of sphere 1702 is covered with nanometer scale assemblies, suchas a series of nanotubes, that are mounted to the surface with someslack, as described above with respect to FIGS. 11-16.

Electromagnets 1704, 1706, 1708, 1710, 1712 and 1714 may be poweredfrom, for example, a battery or some other source. In any case, externalpower is provided to electronics core 1716 that is then provided to theappropriate electromagnets, as described below.

Assuming sphere 1702 is located in a fluid maintained at non-zerotemperature, when one electromagnet is energized, such as electromagnet1704, the resultant magnetic field 1718, along with the nanotubeassembly, lowers the fluid pressure immediately above the surface. Thereduced pressure causes sphere 1702 to move in direction 1720 (if thepropulsion force is strong enough). If, for example, electromagnet 1710is also energized, thereby establishing magnetic field 1722, a force1724 also affects sphere 1702. In this instance, sphere 1702 would bepropelled along a vector 45 degrees away from magnetic axes 1718 and1722 (as shown by arrow 1726). By varying the current supplied to eachof the electromagnets, the movement of sphere 1702 through a fluid canbe controlled.

From the foregoing description, persons skilled in the art willrecognize that this invention provides nanometer scale electromechanicalassemblies and systems that may be used to convert one form of energy toanother. These assemblies and systems may be used to provide, forexample, heat engines, heat pumps or propulsion devices. In addition,persons skilled in the art will appreciate that the variousconfigurations described herein may be combined without departing fromthe present invention. For example, the nanotubes shown in FIG. 4 may bemounted directly to piezoelectric generators of FIG. 4, instead of theconfiguration shown. It will also be recognized that the invention maytake many forms other than those disclosed in this specification.Accordingly, it is emphasized that the invention is not limited to thedisclosed methods, systems and apparatuses, but is intended to includevariations to and modifications thereof which are within the spirit ofthe following claims.

I claim:
 1. An energy conversion system that is immersed in a workingsubstance having a plurality of molecules, said system comprising: abase member; and a plurality of nanometer scale assemblies that convertenergy from one form to another coupled to said base member, each ofsaid nanometer scale assemblies comprising: a molecular impact mass thatreduces the velocity of said molecules that impact said impact mass,said impact mass being restrained to move within a predetermined rangeof distance.
 2. The energy conversion system of claim 1, wherein saidimpact mass further comprises a generator device that converts kineticenergy of said impact mass, resulting from said molecules impacting saidimpact mass, into a different form of energy.
 3. The energy conversionsystem of claim 2, wherein said impact mass is electrostaticallycharged.
 4. The energy conversion system of claim 3, wherein said impactmass comprises a gas molecule.
 5. The energy conversion system of claim4, wherein said gas molecules are restrained by being located in anenclosed carbon nanotube.
 6. The energy conversion system of claim 5,wherein a first half of said plurality of assemblies comprises nanotubescontaining at least one positively charged gas molecules and a secondhalf of said plurality of assemblies comprises nanotubes containing atleast one negatively charged gas molecule.
 7. The energy conversionsystem of claim 2, wherein said generator device comprises anelectromotive force generator that converts kinetic energy intoelectrical energy.
 8. The energy conversion system of claim 7, whereinsaid electromotive force generator comprises: a plurality of nanometermembers each of which is loosely mounted between an individual pair ofsaid first and second mounting points that are fixed to said base membersuch that slack exists in each of said nanometer members; and anexternal magnetic field that, when applied to said nanometer members, ifsaid nanometer members are moving, induces a voltage between said firstand second mounting points.
 9. The energy conversion system of claim 8,wherein said nanometer member is electrically resistive.
 10. The energyconversion system of claim 9, wherein said base member is thermallyconductive, said system further comprising: a first electrically andthermally conductive rail, said first plurality of mounting points beingconnected to said first rail, said first rail being connected to saidbase member; and a second electrically and thermally conductive rail,said second plurality of mounting points being connected to said secondrail, said second rail being connected to said base member.
 11. Theenergy conversion system of claim 10, wherein Brownian motion of saidnanometer members through said external magnetic field generates avoltage across each individual pair of first and second mounting points.12. The energy conversion system of claim 11, wherein said voltagegenerates an electrical current that flows from a first nanometer memberto said first rail, through a second nanometer member, through saidsecond rail, and to said first nanometer member.
 13. The energyconversion system of claim 12, wherein said current causes saidnanometer members and said first and second rails to heat up, saidthermal energy being transferred from said first and second rails tosaid base member.
 14. The energy conversion system of claim 13 furthercomprising: a layer of thermal insulation mounted to a surface of saidbase member between said base member and said nanometer members, saidinsulation substantially covering said surface of said base member. 15.The energy conversion system of claim 8, wherein said nanometer membercomprises a carbon nanotube.
 16. The energy conversion system of claim8, wherein said base member is thermally conductive, said system furthercomprising: a resistor electrically coupled between said first andsecond points and thermally coupled to said base; and a plurality ofthermoelectric generators comprising first and second thermallyresponsive members and a pair of generator output leads, each of saidfirst thermally responsive members being coupled to said base member,each of said output leads being coupled together in series.
 17. Theenergy conversion system of claim 2, wherein said impact mass comprises:a nanometer member loosely mounted between a pair of said first andsecond mounting points that are fixed to said base member such thatslack exists in said nanometer member; and an external magnetic fieldthat, when applied to said nanometer member, if said nanometer member ismoving, induces a voltage between said first and second mounting points.18. The energy conversion system of claim 1, wherein said nanometerscale assembly further comprises: a generator device that convertskinetic energy of said impact mass, resulting from said moleculesimpacting said impact mass, into a different form of energy.
 19. Theenergy conversion system of claim 18, wherein said generator device isan electromagnetic generator that converts mechanical energy intoelectromagnetic energy.
 20. The energy conversion system of claim 18,wherein said impact mass comprises a carbon nanotube.
 21. The energyconversion system of claim 20, wherein said base member comprises aconductive lower plate.
 22. The energy conversion system of claim 21further comprising: an upper conductive plate; and a source of potentialthat, when applied, generates an electric field that creates a forcethat is applied to said impact masses causing said impact masses toremain generally perpendicular to the surface of said lower conductiveplate.
 23. The energy conversion system of claim 18, wherein saidgenerator device is coupled between said impact mass and said basemember.
 24. The energy conversion system of claim 23, wherein saidgenerator device is a piezoelectric generator having a pair of outputleads.
 25. The energy conversion system of claim 24, wherein motion ofsaid impact mass is limited to being substantially between a neutralpoint and a single limit point.
 26. The energy conversion system ofclaim 25, wherein said piezoelectric generator produces a pulsating DCoutput.
 27. The energy conversion system of claim 26, wherein said eachpair of said output leads are coupled together in series to provide asystem output.
 28. The energy conversion system of claim 26, whereinsaid each pair of said output leads are coupled together in parallel toprovide a system output.
 29. The energy conversion system of claim 24,wherein said generator device further comprises: a resistor coupledbetween said pair of output leads.
 30. The energy conversion system ofclaim 29, wherein said generator device further comprises: athermoelectric generator comprising a hot side thermally coupled to saidresistor and a cold side; and a thermally conductive member coupled tosaid cold side.
 31. The energy conversion system of claim 30, whereinsaid generator device further comprises: a first layer of thermalinsulation between said resistor and said working substance; and asecond layer of thermal insulation between said thermoelectric generatorand said working substance.
 32. The energy conversion system of claim30, wherein said thermoelectric generator further comprises: a pair ofoutput leads.
 33. The energy conversion system of claim 32, wherein saideach pair of said output leads are coupled together in series to providea system output.
 34. The energy conversion system of claim 33, furthercomprising: a load resistor thermally isolated from said workingsubstance, said system output being coupled to said load resistor. 35.The energy conversion system of claim 34 further comprising: a thermallyconductive housing that contains said base member, said plurality ofnanometer scale assemblies and said working substance.
 36. The energyconversion system of claim 35, wherein said energy conversion systemoperates as a heat pump that cools an external substance.
 37. The energyconversion system of claim 35, wherein said energy conversion systemoperates as a heat pump that heats an external substance.
 38. The energyconversion system of claim 35 further comprising: a heat engine coupledbetween said housing and said load resistor.
 39. The energy conversionsystem of claim 32, wherein said each pair of said output leads arecoupled together in parallel to provide a system output.
 40. The energyconversion system of claim 29 further comprising: a heat engine having ahot side coupled to said resistor and a cold side coupled to a heatsink.
 41. The energy conversion system of claim 18, wherein saidgenerator device comprises an electromotive force generator thatconverts kinetic energy into electrical energy.
 42. The energyconversion system of claim 18, wherein said generator device is apiezoelectric generator.
 43. The energy conversion system of claim 42,wherein said impact mass comprises a compressible portion of saidpiezoelectric generator.
 44. The energy conversion system of claim 1,wherein said nanometer scale assembly further comprises: a restrainingmember that limits motion of said impact mass within a predeterminedrange of distance.
 45. The energy conversion system of claim 44, whereinsaid restraining member is coupled between said impact mass and saidbase member.
 46. The energy conversion system of claim 1, wherein saidmolecular impact mass contributes, at least in part, to restrainingmovement of said impact mass within a predetermined range of distance.47. The energy conversion system of claim 1, wherein said workingsubstance is a working fluid.
 48. The energy conversion system of claim47, wherein said working fluid comprises a first substance laden withparticulates of a second substance.
 49. The energy conversion system ofclaim 48, wherein said second substance comprises a carbon-basedmolecule.
 50. The energy conversion system of claim 47, wherein saidworking fluid is a liquid.
 51. The energy conversion system of claim 47,wherein said working fluid is a gas.
 52. The energy conversion system ofclaim 51, wherein said gas is air at atmospheric pressure.
 53. Theenergy conversion system of claim 51, wherein said working substance isa heavy molecule gas.
 54. The energy conversion system of claim 53,wherein said heavy molecule gas is xenon gas.
 55. The energy conversionsystem of claim 47, wherein said working fluid is at an elevatedpressure.
 56. The energy conversion system of claim 1, wherein saidmolecular impact mass comprises a nanometer scale paddle.
 57. The energyconversion system of claim 56, wherein said nanometer scale paddle is asilicon paddle.
 58. The energy conversion system of claim 56, whereinsaid nanometer scale paddle is a carbon paddle.
 59. The energyconversion system of claim 56, wherein said impact mass furthercomprises: a plurality of carbon nanotubes, each of which is mounted atone end to said paddle.
 60. The energy conversion system of claim 1further comprising: a three-dimensional object having an exteriorsurface, said plurality of nanometer scale assemblies being mounted tosaid exterior surface, said object being immersed in said workingsubstance.
 61. The energy conversion system of claim 60 furthercomprising: a drive system that varies operation of said plurality ofnanometer scale assemblies such that assemblies on one portion of saidobject create a pressure differential in comparison to operation of saidplurality of assemblies on a different portion of said object, saidpressure differential creating a net force on said object.
 62. Theenergy conversion system of claim 61, wherein said drive systemcomprises: a plurality of electromagnets.
 63. The energy conversionsystem of claim 61, wherein said pressure differential operates topropel said object through said working substance.
 64. The energyconversion system of claim 1, wherein said impact mass has a first endfixed to said base member that operates, at least in part, to restrainmovement of said impact mass within a predetermined distance, and asecond end that is free to move, collisions between said second ends ofdifferent impact masses creating friction that converts kinetic energyof said impact masses into thermal energy.
 65. The energy conversionsystem of claim 64, wherein said impact mass comprises a carbon nanotubeand said base member comprises a thermally conductive material.
 66. Theenergy conversion system of claim 65 further comprising: a heat enginehaving a hot side coupled to said base member and a cold side coupled toa heat sink.
 67. The energy conversion system of claim 1, wherein saidimpact mass comprises a compressible portion of a piezoelectricgenerator.
 68. The energy conversion system of claim 1, wherein saidimpact mass converts energy from one form to another and operates torestrain itself from moving beyond a predetermined range of distance.69. The energy conversion system of claim 68, wherein said impact masscomprises a carbon nanotube.
 70. An energy conversion system that isimmersed in a working substance having a plurality of molecules, saidsystem comprising: a thermally conductive base member; a plurality ofnanometer scale assemblies that convert energy from one form to anothercoupled to said base member, each of said nanometer scale assembliescomprising: a molecular impact mass that reduces the velocity of saidmolecules that impact said impact mass, said impact mass beingrestrained to move within a predetermined range of distance andcomprising a nanometer member loosely mounted between a pair of saidfirst and second mounting points that are fixed to said base member suchthat slack exists in said nanometer member, said impact mass furthercomprising a generator device that converts kinetic energy of saidimpact mass, resulting from said molecules impacting said impact mass,into a different form of energy; and a resistor coupled between saidfirst and second mounting points and thermally coupled to said basemember; at least a first layer of thermal insulation between saidworking substance and said thermally coupled resistor and base member;at least one heat engine comprising: a HOT side thermally coupled tosaid base member; and a COLD side thermally coupled to a heat sink; andan external magnetic field that, when applied to each of said nanometermembers, if said nanometer member is moving, induces an electric fieldthat induces current to flow.
 71. A method of using an energy conversionsystem immersed in a working substance having a plurality of moleculesto convert energy from one form to another, said system comprising abase member and a plurality of assemblies each of which comprises animpact mass that is restrained to move within a predetermined range ofdistance, said method comprising: generating kinetic energy fromstatistical variations in molecular impacts of said molecules on saidimpact mass; converting said kinetic energy to another form of energy.72. The method of claim 71, wherein said another form of energy ispulsating DC electrical energy.
 73. The method of claim 72, whereinconverting comprises: providing an individual output from each of saidplurality of assemblies; and coupling said plurality of individualoutputs together in series to create a system output.
 74. The method ofclaim 73 further comprising: providing a resistive load across 'saidsystem output, said resistive load being thermally isolated from saidworking substance.
 75. The method of claim 71, wherein said another formof energy is radiated electromagnetic energy.
 76. The method of claim71, wherein said another form of energy is AC electrical energy.
 77. Themethod of claim 76 further comprising: reconverting said AC electricalenergy into thermal energy.
 78. The method of claim 77 furthercomprising: converting said thermal energy into DC electrical energy.79. The method of claim 78, wherein said converting said thermal energycomprises: applying a plurality of thermoelectric generators to saidsystem, each of said thermoelectric generators having a pair of outputleads that are coupled together in series; and outputting a systemoutput from said plurality of series-connected output leads.
 80. Themethod of claim 79 further comprising: providing a resistive load acrosssaid system output, said resistive load being thermally isolated fromsaid working substance.